Apparatus for mixing gas and air.



E. A. REEVES.

APPARATUS FOR MIXING GAs AND AIR.

APPLlCATlDN FILED NOV. 26, I915- Patented D00. 12, 1916.

3 SHEETS-SHEET l- E A. REEVES. I

APPARATUS FOR M|X|NG GAS AND AIR.

APPLICATION FILED NOV, ZBI |9I5- I 1,208,654. Patented Dec. 12,1916.

3 SHEETS--SHEET 2.

E. A. REEVES.

APHRATUS FOR MIXING GAS AND AIR.

APPLICATION FILED NOV. 26. 1915.

1 208 654. Patented Dec. 12,1916. 9 3 shuts-4mm 3.

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ford in the county of pressure between "in the several figures;

UNITED STATES PATENT OFFICE.

Enwnv A. REEVES, or MILFORD, CONNECTICUT.

APPARATUS FOR MIXIhT G GAS AND AIR.

v Specification of Letters Patent.

Patented Dec. 12,1916.

Application filed November 26, 1915. Serial No. 63,692.

To all whom itmay concern:

Be it knownthat V citizen of the United States, residing at Mil- NewHaven and State of Connecticut, have invented certain new and usefulImprovements in Apparatus for Mixing Gas and Air, of which the followingis a specification, reference being had therein-to the accompanyingdrawings,

My invention relates to a new and improved apparatus for mixing gas andair, having for its object, among other things, to produce a devicehaving this function wherein the relative air may be in'edetermined andvaried, irrespective of the pressure under whicheither the air or gas isadmitted, and will also maintain the mixture .in. uniform proportionseven tliiough the pressure of the air or gas varies; and furthe 1-, toso construct and arrange the several elel'nents that differentialfriction between the several valves and their connecting mechanisms Willbe entirely eliminated, as well as any difl'erential the air and gasdiaphragms. I

To these, and other ends, my invention consists in the iin 'iroved'apparatus for mixing gas and air, having certain details of constructionand combinations of parts, as will be hereinafter described and moreparticuhu-ly pointed out in the claims. I

Referring to the drawings, in which like nui'nerals of referencedesignate like'parts Figure-l is a fragn'ientary side elevation of myimproved apparatus tan'i'l 'ileteg Fig. 2 is a fragmentary plan viewthereof; 'Fig. 3 is a sectional view of the upper portion of theapparatus, taken upon line C-D of Fig. 2; Fig. a sectional plan. view,taken upon line A-B of Fig. 1; Fig. 5 is an enlarged View of some of theparts. taken upon line F-F of Fig.

I,-Emvnv A. REEVES, a.

proportions of gas and I and sold thij purpose have been complicated,costly, an tory in their-operation and produce an an for various otherreasons, unsatisfac stable and variable product, so much so as tomaterially impair theusefulness and efii ciency of the device. It hasbeen common practice to successfully pumpair and gas through a pipe airand gas are supposed to mix without the aid of mechanical devices, andthereafter in anassumed mixed condition the gas and a r are conveyed tothe point of eonsulnp-g tron, assisted by a pump or similar. means;Another method in more or less common is to preliminarily change thepressure of either the gas or air or both so that it may i entertheapparatus at a constant predeterinto a reservoirwhere the minedpressure; and still another method is to produce the desired resnlt'bythe use of ports or inlets with means for varying dis proportionatelythe areas of said orts or inlets. This .result is accomplis ed bymechanism that is extremely simple in deslgn and construction, com d ofm;

paratively few parts and can be at the minimumcost.

The mechanism is designed and arranged produced so as to be practicallyautomatic and operates without the intervention and assistance ofpistons, gears, and other similar ,,devices commonly used in apparatusof this chin"- aeter heretofore made. T For purposes of illustration Iwill that the gas admitted into my apparat'ns is' the illuminating g susually delivered in cities, through the ordinary city main, and thepressure will vary at difl'erent times during-the day. In that thepressure will not be constant, although, of course, if the pressure is,in fact constant the device will operateequallyas well. v One advantageof having a device capable of operating undir a variable; gas pressureis the fact that it may be used without modification or alteration atany place where there is a. gas supply. H

Between my apparatus-and the point. of consun'u'ition a suction pump isutilized to perform the double function of drawing air and gas throughthe apparatus andforc-' with such will relieve lify the suctionexcessive 'n'essure and will nulfact we can conclude.

by-pass or automatic valves as" action of the pump at a pie:

determined pressure. Such pump' and automat1c mechanism 1s not new ornovel, as

any one of numerous forms of pumps andmechanism may be utilized, all ofwhich are common in the art and readily procurable in the open market.

In the embodiment of the invention I provide a body member 1, which isdivided by the partitions 2 and?) into three compartments or chambers,severally designated 4,

and 6, the chamber 4 being the gas chamber, 5 the air chamber, and 6 thevacuum chamber. \Vithin each of these chambers is a flexible diaphragm 7of a form and construction common in the gas meter art.

- Through the partition 2 is an opening 8 i ,in the interior of the adacent diaphragms within the air and gas chambers, whereby the pressure'within these two diaphragms will always be equal. Air is admitted intosaid diaphragms tln'oughthe port 87, during\ the expansion thereof, andexhausts therefrom during their contraction.

ithin each of the chambers 4, 5 and 6 is a rock shaft, the same beingseverally designated 9, 10 and 11, and each s ]()11 Il1'21ld at itslower end 111 a block 12, and at its up- .per end projects through thetop of the body member and is journaled in a sleeve 13. Each rock shaftis connected with the adjacent diaphragm by an arm-14, which is securedat one end in a fixed relation to the shaft, and at the other end to thediaphragm by'the pin 15 that passes through the posts 16 forming partthereof.

The lateral movement of the diaphragms,

-all of which are shown in their contracted relation, during theirexpansion and con traction, impart a rocking moven'ient to the shafts 9,10 and 11, through the arms 14, as above described,

The numeral 17 designates the gallery member, which, by means of thepartitions 18, 19 and 20, is divided into a plurality of chambersseverally designated as follows;- 21 the air chamber, the gas chamber,23 the exhaust chamber, 24 the gas inlet chamber, and 25 the air inletchamber. The exhaust chamber 23 terminates in a cylindrical neck portion26, having a threaded head 27 thereon to provide convenient means forcoupling a pipe thereon. The gas chamber 22 is connected with theexhaust chamber 23 by the port 28, andthe air chamber 21 by the port 29.A branch 30 projects laterally from the gallery member 17, is supportednear its outer end by a standard 55, and opens into the gas inletchamber 21 to provide means whereby a supply of gas is admitted into.said chamber, and a similar branch 31 opens into the chamber 25 andprovides means for admitting a. supply of air thereto. connected withthe exhaust chamber 23 through the pipes and coupling 34 and The vacuumcompartment 6 is the gas chambers 22 and 4 by the pipes 35; and cdupling36, and. the air chamber 21 with the air compartment 5 by means of thepipes? and coupling 33. Slidablymounted within the chamber 22, so as tocover and uncover the port 28, is the valve 38 and a similar valve 39 isprovided in the air chamber 21 to cover and uncover the port 29. Areciprocatory movement is imparted to these valves through rock shafts40 and 41, to which are fixed the rock arms 42 and 4-3, these latterbeing connected with the valves through the links H and Gravity willhold these valves upon their seat, but if it is desired to positivelyprevent them from shifting their parallel position thereon, any simplemeans may be provided that will accomplish this result. One form of suchmeans is illustrated, and consists in the guide rods 86 that are held ina fixed position and project through the lugs 46 upon the valves 38 and39. By this mechanism the "alves are always held in a proper position,laterally and upon their contact surface.

Th gas inlet chamber 24 is connected with the gas chamber 22 by the port47 and the air inlet chamber 25 by the port .48. These ports 47 and 48are respectively covered and uncovered by valves 49 and 50 which arehinged upon the arms 51 and 52zupon the rock shafts 53 and 54, and aremoved toward and awayfrom the valve seat in a rotary path as theseshafts move about their axes.

Fixed to the rock shaft 9 is an arm 56 and to the rock shaft 5-L an arm57, and these are connected by a link.58 so that movement of the shaft 9is transmitted to the shaft 54. Similar mechanism imparts movement tothe shaft 53, an arm 59 being fixed to the rock shaft 10, an arm 60 tothe rock shaft 53, and

a link 61 connecting the outer ends of bothof said arms.

Connecting the arms 62 and 63, respectively fixed to the rock shafts 9and 10, is the spring 64, which exerts a. uniform and equal pressure inone direction upon both of the shafts 9 and ,lllfor a purposehereinafter to be described.

Journaled in the fixed lugs65 is a rock shaft 66, which is actuated fromthe rock shaft 11 through the arms 67 and 68, joined by the link 69. Thelink 69 and arm 67 are pivotally connected by a swivel pin 70 rotatablymounted in the arm 67 and having a stud 71 projecting therethrough, towhich is secured one end of the spring 72, the other end being securedto a lug 73 on the body member 1. This spring always exerts its tensionso as to move the rock shaft 11 in a direction that will impart acompression action to the diaphragm in'the 'acuum chamher 6.

Motion is transmitted to the rock shaft 40 from the rock shaft 66through the arm 7 4 fixed to the shaft 66, the sector arm 7 5. fixedmeson to the sliaft 40 n'ndthe link 76 between said arms. The arm isprovided with a slot 77 within which slides the stud 7 S that providesm'eans for connecting the link 7 6 therewith. A screw 79 is 'rotdtablymounted in the block pivotally secured to the sector arm 7 5 and isthreaded "through the stud 7 8, being rotated by the thumb nut 81. Bythis mechanism means is provided for varying the elative point t.connection between the link '76 and arm 75 so as to vary the length ofmovement of the rock shaft -10 and thus provide means for varying thelength of stroke of the valve 38.

The rock shaft 41 is actuated from the shaft 66 through the link 82 thatis secured at one end to the arm 83 upon the said shaft 41 and at theother end to the arm 84 on the shaft 66, said link being provided at oneend with nuts threaded thereon so as to vary the length of said link andthus pro vide 'a relative adjustment of the parts.

The ports 28 and 29 are shown as triangula r in shape and by reasonthereof only open gradually, thus producing a more perfect operation ofthe mechanisms. So far as at presentadvised, I am the first to use atriangular port in a device of this character, and while the devicemight operate to advantage with a port of a difierent shape, yet I am ofthe opinion that a triangular port is more desirable.

Now, in describing the operation of the mechanism, we will assume thatall of the ports are closed and the parts are in the same relativeposition that they occupy in Fig. 2 with air at atmospheric or otherpres sure, being within the chamber 25, a source of gas supply at anypressure within the gas chamber '24, no mixture of the air and gas istaking place, no product is passing from the apparatus, and all of themechanism is at rest. It is the practice to facilitate the distributionof the product by a suction pump which is fixed in the conductor pipesomewhere between the apparatus and the point of consumption, which pumpand its method of operation are common in the art and of course are notherein shown. (ms is admitted through the branch 30 and fills thechamber 24 and air is admitted through the branch 31 into the chamber25, and both of these chambers are filled under pressures haviu norelation to each other and may be varicr as conditions change. The airand gas united into the desired mixture, and as :1 finished product,passes out through the chamber 23 and neck 26 into a pipe whichconducts-a it to the point of consumption. l'nunodiately the supply isturned on at. any )oint of consumption, the mixture in the oxmustcluunbcr passes tlu'u'vthrough and creutos a vacuum within the chamber23. which is transmitted through the pipes 32 into the vacuum chamber 15and the diaphragm therein immediately begins to expand. This expansioncauses a rocking movement of the shaft 11, which is transmitted to thevalves 3S and 39 through the rock shafts 66, t0 and 41, and said valvesbegin to slide upon their seat and uncover the ports 28 and 29. Thisvacuum then passes through said ports 2-8 and 29 into the chambers '21and 22 through the pipes 35' and 37 into the chambers 4 and 0. At thistime the diaphragms in each of the chambers i and 5 begin to expand,causing the shafts J and 10 to rotate and thereby lift the valves 49 and50 oil their seat and admit gas and air respectively from the gas inletchamber 24 into the gas chamber 22 and from the air inlet chamber intothe air chamber 21, which then pass respectively through the ports 28and 29 and unite in the chamber 23 in the same proportions as theuncovered portions of the ports 28 and 29 bear to each other. Thismixture is then drawn through the neck portion 26 by the suction in theconductor pipe and passes on to the point of consumption. Variation inthe extent of movement of the valves 38 and 39 determines the extent ofthe opening of the ports 28 and 29 and thereby determines the relativeproportion of air and gas in the mixture, and this relative extent ofopening is varied by manipulation of the screw 79 through the thumb nut81 which shifts the position of the stud 78 within the arm 75 and thusvaries the length of stroke of the valve 38. In this construction itwill beobserved that the proportioning valves 38 and 39 are operated bythe diaphragm within the chamber 6 and that the valves to admit gas andair are separately operated by a single diaphragm within the chambers 4and 5 respectively, thus leaving the air and gas diaphragms burdenedonly with a single valve, thereby placing no undue or diiferentialburden upon either diaphragnn The air entering through port 48 and gasthrough port l7 into chambers 21 and respectively, are at a balancedpressure, by reason of the action of the diupliragms in chambers l and5, which operate valves 49 and 50 covering said ports. Therefore theamount of gas and air that passes through the triangular ports 28 and.49 must be in exact proportion to their relative exposed areas,

There are minor changes and alterations that can be made within myinvention, aside from those herein suggested, and I would there-forehave it understood, that .I do not limit myself to the exactcoustrlmtion herein shown and descriluul, but claim all that .fullsfairly within the spirit and scope of my invention.

Having described my invention. what 'I' claim as new. and desire losl'u'ul'u by Letters Patent. is:----

I. In an apparatus of the character doscribed, the combination with abod member, having separate air and gas in ets and an exhaust outlet; ofmeans, Within Stlld body member, for mixin in predetermined proportionsthe air ant gas that passes through said inlets, irrespective of therelative pressure under which the air and gas enter said body member anddelivering said mixture to said exhaust outlet; and means for varyingsuch predetermined proporlions.

In an apparatus of the character de scribed, the. combination with abody memher. having separate air and gas inlets and an exhaust outlet:of means, Within said body member for mixing in predeterminedproportions the air and gas that passes throuu'h said inlets,irrespective of the relative pressure under which the air and gas entersaid body member and delivering said mixture to said exhaust outlet, andmaintaining the same at said exhaust Outlet in the same relativeproportion; and means for varving such predetermined proporlions.

3. In an apparatus of the character described, the combination withmeans for in dependently receiving air and gas at varyiug and dilferentpressures, w1th means for separately reducing said air and gas to apressure less than atmospheric pressure; means for holding said air andgas balanced at the same pressure; means for uniting the air and gasinto a common mixture and in predetermined proportions; and means forvarying such predetermined proportions.

at. In an apparatus of the character described, the combination with abody member, having a vacuum chamber, a gas chamber, and an air chambertherein; of a gallery member, having an air chamber, a gas chamber and avacuum chamber therein; means for connecting both of said vacuumchambers; means for connecting both of said air chambers; means forconnecting both of said gas chambers: valve controlled means foradmit-til'ig air into the air chamber in said gallery member; means foradmitting gas into the gas chamber in said gallery member; a portconnecting each of said gas and air chambers in said gallery men-metwith the vacuum chamber therein; a valve for cunning and uncovering saidport; and means. controlled by thediaphragm within the vacuum chamberwithin said body incinher for operating said valves.

In an apparatus oi the character descrihed, the combination with a bodymember. having a plurality of chamber therein; a lfliaphragm in each ofsaid clu'unbcrs; a gallery member. having! a plurality of chamberstherein. and connected with said body Inelnlmr; valve means forcontrolling the flow of oil. into one of the clmlnbcrs in said gallerymember; menus for opcratlvely connccting said valve means with one ofsaid diaphragms; valve means for controlling the [low of gas into one ofthe chambers in said gallery member; means for 0 eratively connectingthe last mentioned va re means with another of said diuphragms; aplurality of valves for controlling the [low of air and "as from saidchambers into another chamber in said gallery member; and means,operatively connected with another of said diaphragms for actuating allof said latter valves.

(3. In an apparatus of the character descril =ed, the combination with abody member, having a. vacuum chamber, a gas chamber, and an air chambertherein; of a gallery member, ha ving an air chamber, a gas chamber anda vacuum chamber therein; means lor connecting both of said vacuumchambers; means for connecting both of said air chambers; means forconnecting both of said gas chambers; valve controlled means foradmitting air into the air chamber in said gallery member; means foradmitting gas into the gas chamber in said gallery member; a portconnecting each of said gas and air chambers in said gallery member withthe vacuum chamber therein; a valve for covering and uncovering saidport; and means, controlled by the diaphragm Within the vacuum chamberwithin said bod memher for operating said valves, all of said alvesbeing primarily controlled by the suction within said vacuum chamber.

7. In an apparatus of the character described, the combination with acontaining member having a plurality of chambers therein, an air inletconnection into one of said chambers,a gas inlet connection into anotherof said chambers a vacuum chamber having connection with both of theaforesaid chambers, a plurality of air filled diaphragms, valves foropening and closing the connection between some of said chambers, themovement of said valves and the admission of air and gas to theapparatus being primarily controlled by the suction within said vacuumchamber.

8. In an apparatus of the character described, the combination with acontaining member, having separate air and gas inlets and an exhaustoutlet; of diaphragm actuated means for controlling the flow of air andgas in said crmtaining member; diaphragm means for mixing inpredetermined proportions the air and gas that pass tl'irongb said.inlets, irrespective of the relatire pressure under which the air andgas enter said containing member, and deliver said mixture to saidexhaust outlet said latter diaphragm actuated means being separated fromsaid first mentioned diaphragm actuated means; and means for varyingsuch |n'cdctel'ulined pro 'iortions.

9. In an ammratus of the character described, the combination with acontaining member, having separate air and gas inlets and an exhaustoutlet; of diaphragm actuated means for mixingin predeterminedproportions the air and gas that pass through Said inlets, irrespectiveof the relative pressure under which the air and gas enter said bodymember and delivering said mixture to said exhaust outlet, andmaintaining the same at said exhaus outlet in the same relativeproportion; and diaphragm operated means for varving such predeterminedproportions, said latter diap irogni means being separate andindependent from the first mentioned diaphragm means.

10. In an apparatus of the character described, the combination with abody memher, having therein an air chamber, a gas chamber and a vacuumchamber; of a gallery member connected therewith, having an air inletchamber, an air chamber, a gas inlet chamber, a gas chamber and a vacuumchamber; a diaphragm in each of the three first mentioned chambers; aport connection between both of said air chambers; a port connectionbetween both of said gas chambers; a ort connection between the airinlet chnmber and air chamber in said gallery member; a, port connectionbetween said gas inlet chamber andgas chamber in said gallery member;-valves for closing both of said latter ports each being actuated by adie hra within one of the chambers in mi bo y member; a port connectionbetween the air chamber in said gallery memher and said vacuum chamber;a port connection between. said gas chamber in said gallery member andthe vacuum chamber therein; a: valve-movable in relation to said latterports to cover and uncover the same; and means for actuating both ofsaid valves from a single diaphragm in one of the chambers in said bodymember, said diaphragm being independent and separate from the aforesaidchaphragms.

11. In: an apparatus of the character described, the combination with abody member, having therein. an air chamber, a gas chamber anda vacuumchamber; of a gallery member connected therewith, having an air inletchamber, an air chamber, a gas inlet chambcn, a gas chamber and a vacuumchamber; a dinphca. in each ofthe three lirstmentioned. cha n crs; a,port connection betweenboth. of said air chambers; a portconnectionbetween both of said as chambers; a orb, connection between te air inlet cham m and air chamber in said gallery member; a portconnection between said gas inlet chamliieu and. gas chamber in. saidgullcry member; valves for closing both of said latter ports. each beingactuated bun diaphnagin withinono of the chambers "I said lolly mombcr,said valves being independant-1y movable, m, a. rotary path; aportconnection between the air chamber in said gallery member and saidvacuum chamber; a port connection between said gas chamber in saidgallery member and the vacuum chamber therein; a valve movable inrelation to said latter ports to cover and nocover the same; and meansfor actuating both of said valves from a single diaphragm in one of thechambers in said body member,

diaphragm being independent and separate from the aforesaid diaphragms.

12. In an apparatus of the character described, the combination with abody member, having therein an air chamber, a gas chamber and a vacuumchamber; of a galler Y member connected therewith, having an air inletchamber, an air chamber, a gas inlet chamber, a gas chamber and a vacuumchamber; a diaphragm in each of the three first mentioned chambers; aport connection between both of said air chambers; a port connectionbetween both of said gas chamhers; a port connection between the airinlet chamber and air chamber in said gallery member; a port connectionbetween said gas inlet chamber and. gas chamber in said gallery member;valves for closing both of said latter ports, each being actuated by a.diaphragm within one of the chambers in said body member; a, portconnection between the air chamber in said gallery member and saidvacuum chamber; a port connection between said as chamber in saidgallery member and t e vacuum chamber therein; a valve movable inrelation to said latter ports to cover and uncover the same; means foractuating both of said valves from a single diaphragm in one of thechambers in said body member, said diaphragm being independent andseparate from the aforesaid diaphragms; and means for varying therelative length of movement of each of said latter valves.

13. In an apparatus of the character described, the combination with abody member, having therein an air chamber, a. gas chamber and a vacuumchamber; of a gallery member connected therewith, having an air inletchamber, an air chamber, a gas inlet chamber, a. gas chamber and avacuum chamber; a diaphragm in each of the three first mentionedchambers; a port connection between both of said: air chambers; a. portconnection between both of said gas chamhers: a port connection betweenthe air inlet chamber and air chamber in said gallery member; a portconnection between said gas inlet chamber and gas chamber in saidgallcry member; valves for closing both of said latter ports. each beingactuated by a diuphragm within one of the chambers in said body member,said valves being mounted upon independent rock shafts; a portconnection between the air chambm: in said gul- Icry member and. saidvacuum UhIlJnb01.11

port connection between said gas chamber in said gallery member and thevacuum chamber therein; a valve movable in relation to said latter portsto cover and uncover thesame; means for actuating both of said valvesfrom a single diaphragm in one of the chambers in said body member, saiddiaphragm being independent and separate. from the aforesaid diaphragms;and a connection betwr -n one of the diaphragms in one of the chambersin said body member with said rock shafts. whereby the. expansion orcontraction of said diaphragm will impart movement to said rock shaftabout its axis.

14. In an a iiparatus of the character described, the combination with abody member. having: therein an air chamber. a gas chamber and a vacuumchamber; of a gallery member connected therewith, having an air inletchamber, an air chamber, a gas inlet chamber, a gas chamber and a vacuumchamber; a diaphragm in each of the three first mentioned chambers; aport connection between both of said air chambers; a port connectionbetween both of said gas chambcrs; a )ort connection between the airinlet chum er and air chamber in said gallery member; a port connectionbetween said gas inlet chamber and gas chamber in said gallery member;valves for closing both of said latter ports, each being actuated by adiaphragm within one of the chambers in said body member; a portconnection between the air chamber in said gallery member and saidvacuum chamber: a port connection between said gas chamber in saidgallery memher and the vacuum chamber therein; a valve movable inrelation to said latter ports to cover and uncover the same; means foractuating both of said valves from a single diaphragm in one of thechambers in said body member, said diaphragm bein independent andseparate from the a oresaid diaphragms; and means for simultaneouslyexerting a uniform compression action upon the diaphragms in the air andgas chambers of said body member.

15. In an apparatus of the character described. the combination with abody memher, having therein an air chamber, a gas chamber and a vacuumchamber; of a gallery member connected therewith, having an air inletchamber, an air chamber. a gas inlet chamber. a cas chamber and a vacuumchamber; a diaphragm in each of the three first mentioned chambers; aport connection between both of said air chambers; a port connectionbetween both of said gas chaml'vers; a port connection between the airinlet chamber and air chamber in said gallery member; a port connectionbetween said gas inlet chamber and gas chamber in said gallery member;valves for closing both of said lat-tor ports, each being actuated by ndinphragln within one of the chambers in said body member; a portconnection between the air chamber in said gallery member and saidvacuum chamber; a port connection between said gas chamber in saidgallery memher and the vacuum chamber therein; a. valve movable inrelation to said latter ports to cover and uncover, the same; means foractuating both of said valves from a single diaphragm in one of the.chambers in said body member, said diaphragm bein independent andseparatefrom the af dresaid diaphragms; and yielding means for impartinga compression action to the diaphragm in the vacuum chamber-of said bodymcmbein 16, In an apparatus of the character described, the combinationwith :1 containing member having a vacuum chamber therein; of a gallerymember having a gas chamber; an air chamber and a vacuum chambertherein; a connection between said vacuum chambers; a port connectionbetween said gas chamber and the vacuum chamber in said gallery member;a port connection bctween said air chamber and the vacuum chamber insaid gallery member; and means for covering and uncovering said ports atone and the same time so as to expose a predetermined area thereof,whereby air passing from said air chamber into said vacuum chamber andgas from said gas chamber into said vacuum chamber will enter saidvacuum chamber in relative predetermined proportions.

17. In an apparatus of the character described, the combination with acontaining member having a vacuum chamber therein; of a gallery memberhaving a gas chamber, an air chamber and a vacuum chamber therein; aconnection between said vacuum chambers: a port connection between saidgas chamber and the vacuum chamber in said gallery member: a portconnection between said air chamber and the vacuum chamber in saidgallery member; means for covering and uncovering said ports at one andthe same time so as to expose a predetermined area thereof, whereby airpassing from said air chamber into said vacuum chamber and gas from saidgas chamber into said vacuum chamber will enter said vacuum chamber inrelative predetermined proportions; a diaphragm within the vac-uumchamber within said containing member; and means for actuating saidvalves through an operative connection with said diaphragm.

18. In an apparatus of the character dc.- scribcd, the combination with:1 containing member having a vacuum chamber therein; of a. gallerymember having a gas chamber, an air chamber nnd a vacuum chaml'mrtherein; a. connection between said vacuum chambers: a port connectionbetween said gas chamber and the vacuum chamber in said gallery member;a port connection between said air chamber and the vacuum chamber insaid gallery member; means for covering and uncovering said ports at oneand the-same time so as to expose a predetermined area thereof, wherebyair passing from said air chamber into said vacuum chamber and gas fromsaid gas chamber into said vaciuiun chamber will enter said vacuumchamber in relative predetermined 1.]1'01301t10IlSL/21 diapliragm withinthe vacuum chamber Within said containing member; means for actuatingsaid valves thro rgh an operative connection with said i inphragm; andmeans for adjustingJthe relative position of said "valves, whereby therelative extent of exposed area of said ports may be varied.

19. In an apparatus of the character described, the combination with acontaining member having a vacuum chamber therein; of a gallery memberhaving a gas chamber, an air chamber and a vacuum chamber therein; aconnection between said vacuum chambers; a port connection between saidgas chamber and the vacuum chamber in said gallery member; a portconnection between said air chamber and the vacuum chamber in saidgallery member; means for covering and uncovering said ports at one andthe same time so as to expose a predetermined area thereof, whereby airpassing from said air chamber into said vacuum,

chamber and gas from said gas chamber into said vacuum chamber Wlllenter said vacuum chamber in relative predetermined proportions;a'diaphragm within the vacuum chamber Within said containing mem- EDWINA. REEVES.

